This invention relates to a food additive comprising inulin and colloidal hydrolyzed cellulose. More particularly, this invention relates to a composition and process for making a composition which may be used as a substitute for fat in foods.
The amount of fat, particularly saturated fat, in foods has been linked to potentially unhealthy effects, for example atherosclerosis. Consumers now seek out foods with a reduced fat content or fat-free foods to avoid what is believed to be adverse effects of the fat-containing food.
In response to the desire for foods with low or no fat content, various foods are now on the market which are lower in fat content or in which the fat content has been eliminated. These foods, although lower in fat, require consumers to compromise on the taste and texture of the food in order to benefit from such lower fat-containing foods.
Inulin is a naturally occurring material which-may be obtained industrially from chicory root. Inulin has been used as a fat substitute in foods, and gives the necessary fat-like texture to foods. When inulin is added, as a fat substitute, to a food, the inulin gels slowly, and requires a solid content that is excessive. Additionally, the inulin may be incorporated into certain foods with processing difficulties.
U.S. Pat. No. 5,501,869 teaches a fat mimetic for use in foods which includes a maltodextrin or acid modified starch, a branched chain amylopectin, and, as a texturizing agent, inulin. Microreticulated microcrystalline cellulose is also added to the formulation in order to reduce the sweetness which, the patent teaches, occurs in a non-fat spreadable margarine product and squeezable margarine product which contain inulin at levels above about 23%.
U.S. Pat. No. 5,169,671 is directed to a reduced fat, oil or sugar food, and drink. The patent teaches using a polyfructan as a substitute for such oils, fats and sugars. The patent also teaches that the polyfructan composition has a creamy taste and texture equivalent to that of fats and oils. The ""671 patent teaches a fructose polymer having a beta-2,1 bond as a whole or partial substitute for the fats or oils. The ""671 patent also teaches the use of gelation materials, thickening agents, and low calorie sugars.
U.S. Pat. No. 5,468,512 relates to a fat-replacement ingredient which is an oligofructose such as inulin, irisin and lycorisin. The ""512 patent teaches that oligofructoses of the inulin type, are composed mainly of beta-2,1 bonds, and are used as fat or oil substitutes in food production. The ""512 patent further teaches that preferred oligofructoses are low calorie polysaccharides of the inulin type.
U.S. Pat. No. 5,527,556 is directed to a creamy composition which may comprise inulin, a liquid and other components such as salts, carbohydrates, proteins and gums. The creamy composition may be added to a food product as a fat substitute. Instead of being added to a food product as a creamy composition, the composition of the ""556 patent may be dried and added to a food product as a dry powder provided the food product is sufficiently liquid to hydrate the dry powder.
xe2x80x9cUse ofinulin as a Natural Texture Modifierxe2x80x9d; R. F. Silva, Cereal Foods World; 41 (10), pages 792-794 (Oct. 1996), discloses that inulin juice is concentrated and spray-dried to yield a powder having 96% of dry matter.
xe2x80x9cInnovative food products with inulin and oligofructosexe2x80x9d; Franck-Frippiat, A.; 1st Orafti Research Conference; pages 182-185 (more than one year ago) discloses the diffusion of inulin in hot water followed by refining and spray-drying.
A product brochure directed to Raftiline(copyright) and Raftilose(copyright) inulin and oligofructose, published by Orafti, xe2x80x9c. . . a daughter company of Raffinerie Tirlemontoise.xe2x80x9d (more than one year ago) discloses on page 2 thereof that inulin is extracted from a vegetable source with hot water, purified and spray-dried to a powder. The degree of polymerization of the inulin powder is dependent upon the purification process used prior to spray-drying.
None of the references teach or suggest a fat substitute which comprises inulin and colloidal hydrolyzed cellulose or a process for preparing such a fat substitute.
Broadly, this invention contemplates a composition comprising rod-like colloidal hydrolyzed cellulose particles with lamellar inulin particles.
This invention also contemplates a process for preparing an inulin-colloidal hydrolyzed cellulose composition comprising dissolving or slurrying the inulin in water, adding colloidal hydrolyzed cellulose wet cake to the solution or dispersion, shearing the dispersion of inulin and cellulose to obtain a uniform dispersion, and either forming a paste or spray drying the uniform dispersion having a solids content of at least about 15%.
The spray-dried inulin-colloidal hydrolyzed cellulose compositions of this invention, enhance the performance of the inulin by forming a unique composition of two shapes of particles which are interspersed with one another.
When the composition of this invention is an interspersed composition, the colloidal hydrolyzed cellulose particles cannot be separated from the inulin particles by ordinary physical means such as centrifugation and the like.
An interspersed composition may be prepared by mixing an inulin slurry or solution with a colloidal hydrolyzed cellulose wetcake and subjecting the mixture to shearing or attriting or comilling such as in a colloidal mill.
Shearing involves applying opposing forces to the inulin/colloidal hydrolyzed cellulose wetcake mixture. The opposing forces are close together and application of a shearing force results in a stronger physical attraction or interaction between the inulin particles and the colloidal hydrolyzed cellulose particles.
Attrition is a reduction of the particle size to bring about interspersion.
When the composition is added to a food, as a fat substitute, the addition results in a food which contains a significantly reduced amount of inulin to achieve an improved texture, excellent eating quality, longer shelf life and greater stability than a food which contains inulin alone as received from an inulin manufacturer.
The above benefits are also obtained when the composition is a paste such as will result from adding attrited colloidal hydrolyzed cellulose wetcake to inulin, which may not necessarily have been spray-dried, and shearing the mixture as well as to a composition which is a powder.
In order to achieve all or some of the above benefits, the inventive composition has a number of different aspects:
If inulin, as received from the manufacturer, whether already spray-dried or not, is spray-dried at a solids content of at least 15%, the resultant product, when added to a food may be added to a food in a lesser amount than inulin as received from the manufacturer and will result in an improved viscosity, gel strength, improved texture, good mouthfeel, excellent eating quality, smoothness and the like.
If attrited colloidal hydrolyzed cellulose wetcake is added to spray-dried inulin and the mixture sheared, a paste is formed which has an improved rheology and texture.
If attrited colloidal hydrolyzed cellulose is sheared with inulin as received from the manufacturer a paste may be formed which has an improved texture and rheology.
If colloidal hydrolyzed cellulose wetcake is added to inulin, the mixture sheared, dispersed, homogenized and spray-dried, when the resultant powder is reconstituted in the food or reconstituted prior to addition to the food and used in a food, the food will have an improved texture and rheology.
The particular inventive composition which is used, and its manner of preparation will depend, to a large extent, on the ultimate use of the composition and the type of food with which it is to be used.
Unless specified otherwise, as used in the specification and claims, all percentages given are percent by weight.
The composition of this invention comprises rod-like colloidal hydrolyzed cellulose particles with lamellar inulin particles. The particles are believed to form a network which provides the unique properties of the combination.
The claimed composition may be prepared by dissolving or dispersing inulin in water. Thereafter, a wet hydrolyzed colloidal cellulose filter cake which has been prepared from acid hydrolysis of a cellulose-rich pulp is then attrited to a desired particle size and added to the inulin solution or dispersion. The combination is then sheared to obtain a uniform dispersion. The uniform dispersion is then spray dried or used as a paste.
The inulin used, as received from the manufacturer, may have been spray-dried by the manufacturer when the powder was being made. In practicing this invention one may use either inulin which has not been spray-dried prior to being used in this invention or inulin which has been spray-dried by the manufacturer.
The inulin used is an oligofructose polymer wherein the degree of polymerization of the polymer is from about 4 to about 60 monomeric units. It is preferred however, that the inulin have an average degree of polymerization of from about 7 to about 18 units, more preferably 7 to about 14 units, because optimum results have been obtained thereby.
The inulin particles which are used will have an average particle size of from about 0.1 to about 50 microns, preferably 0.1 to about 20 microns, and most preferably 0.1 to about 5 microns. If the average particle size of the inulin particles exceeds an average particle size of about 20 microns, then the level of effectiveness of the composition may be adversely affected.
The colloidal hydrolyzed cellulose may be prepared by starting with a cellulose-rich pulp and hydrolyzing the pulp with acid. Next, the wet cellulose-containing filter cake is attrited to an average particle size of from about 0.1 to about 10 microns. The average particle size of the attrited wet cellulose-containing filter cake will be preferably less than 1 micron.
There are many sources of cellulose-rich material and any of these sources may be used in preparing the colloidal hydrolyzed cellulose. Among the materials that may be mentioned are plant-derived materials such as soy hulls, corn hulls, nut hulls, wood and the like.
Attrition of the hydrolyzed cellulose particles to form colloidal particles may be accomplished using any suitable apparatus such as a Silverson(copyright) mixer. The choice of mixer will be apparent to one skilled in the art taking into consideration the particle size desired.
When the inulin-colloidal hydrolyzed cellulose composition is to be spray-dried, it should not gel on the way to the spray drier. Whether the composition will gel or not depends on the degree of polymerization of the inulin, the weight ratio of colloidal hydrolyzed cellulose to inulin and the percent of solids in the composition to be spray-dried.
In a preferred embodiment, colloidal hydrolyzed cellulose particles, in the form of a wet cellulose-containing filter cake, which has been attrited to a particle size of from about 0.1 to about 10 microns, are added to the inulin-containing dispersion or solution, and the entire mixture is then sheared to create a uniform dispersion. It is this uniform dispersion, which contains at least 15% solids, which is then spray-dried at an inlet temperature of from about 200xc2x0 C. to about 280xc2x0 C. and an outlet temperature of from about 100xc2x0 C. to about 120xc2x0 C. The resultant spray-dried material will comprise from about 40% to about 98% inulin, and from about 2% to about 60% of colloidal hydrolyzed cellulose and will be a powder having from about 2% to about 8% water.
The spray-dried composition is particularly preferred because powder is easier to transport than a dispersion, and the powder may be easier to incorporate into specific food applications, taking advantage of the water already present.
If it is desired to utilize the spray-dried inulin/colloidal hydrolyzed cellulose composition as a paste, then from about 65% to about 98% of a liquid is added and the mixture sheared to form a paste.
The paste or cream dispersion may be prepared from a composition wherein only the inulin may have been spray-dried. When the composition is prepared from inulin, whether or not it has been spray-dried, and colloidal hydrolyzed cellulose, the composition has the rod-like colloidal hydrolyzed cellulose particles interspersed with the lamellar inulin particles. The composition is sheared until a uniform dispersion is obtained. Thereafter, the composition is used as is, that is, in the form of a paste or cream dispersion. By the term xe2x80x9cpastexe2x80x9d we mean a dispersion which will comprise from about 2% to about 35% of solids, the remainder being liquid, such as water or milk.
Alternatively, one may dissolve or slurry the inulin in water and spray-dry only the inulin at a solids content of at least about 15%. Spray-drying of the inulin will improve the properties of the inulin, regardless of how the inulin was dried previously. The inulin may be used normally in a food or to form a paste, the choice being dictated by the food application in which it is being used.
Inulin is dissolved or dispersed in water, and the resulting solution or dispersion subjected to high shear conditions. The amount of inulin which is added to the water may vary widely so that the dispersion to be spray-dried will contain from about 15% to about 35% of solids by weight of the dispersion: Generally, the greater the solids content of the initial spray-dried composition, the greater the viscosity and stability of a gel formed with the resultant spray-dried composition.
In preparing the inulin solution, inulin is generally dissolved or slurried in water at a temperature of from about 20xc2x0 C. to about 75xc2x0 C. and preferably at about 40xc2x0 C. to about 70xc2x0 C. Inulin is partially soluble in water and the increase in temperature will increase the solubility rapidly. However, if the inulin is allowed to cool, as it cools, it will precipitate.
The inulin dispersion will be spray-dried at an inlet temperature of from about 200xc2x0 C. to about 280xc2x0 C., and an outlet temperature of from about 100xc2x0 C. to about 120xc2x0 C. The spray-dried material contains about 2-6% of water by weight. In practicing this invention, inulin which has been spray-dried in the course of its manufacture will have enhanced properties as a result of being spray-dried according to this invention.
One convenient way to measure the effectiveness of the compositions and process of this invention is to prepare a gel from the various compositions and to measure the viscosity of the gel. Generally, the firmer the gel, the more effective the composition.
The gel may be formed by dispersing an inulin/colloidal hydrolyzed cellulose spray-dried composition in water with high shear at a temperature of from about 40xc2x0 C. to about 75xc2x0 C. The solids content of the gel may vary from about 2%, by weight, to about 35% by weight. This will include all gels wherein the inulin to colloidal hydrolyzed cellulose ratio is as set forth before in describing the composition to be spray-dried. The gel is generally formed at temperatures of from about 30xc2x0 C. to about 40xc2x0 C., depending on the composition. Generally, a gel is considered formed when the viscosity of the gel is at least about 1000 centipoises. The viscosity of the gel may vary from about 1000 centipoises to about 1,000,000 centipoises as determined by a Brookfield RVT viscometer.
In forming the gel using a spray dried composition, the spray dried material (inulin plus colloidal hydrolyzed cellulose) is added to water which is at a temperature of from about 40xc2x0 C. to about 75xc2x0 C. It is preferable, however, that the temperature of the water, when dispersing the spray-dried composition, be above 50xc2x0 C. The gel is formed by adding the spray dried powder to water and subjecting it to medium shear, such as a Silverson(copyright) mixer or by passing it through a homogenizer at low to medium pressure. The resultant material is then allowed to stand for a period of time of from about one minute to about 24 hours, depending upon the solids content of the gel. Gelation is accelerated by subjecting the resultant sheared material to refrigeration.
The gel may also be formed, as described above, using a spray-dried inulin which has been spray-dried more than once without colloidal hydrolyzed cellulose, or inulin which has not been spray-dried plus colloidal hydrolyzed cellulose or spray-dried inulin plus colloidal hydrolyzed cellulose.
Gelation will also be more rapid for a material which has a higher solids content than for a material which has a low solids content. For example, one minute might be required for a 30% solids material to gel, as compared to 240 minutes for a 5% solids material to gel.
The viscosity of the gel formed will be a function of the degree of polymerization of the inulin used, whether the inulin or inulin/colloidal hydrolyzed cellulose has been spray-dried, the solids content of the composition and the ratio of inulin to colloidal hydrolyzed cellulose.
For a given composition according to this invention having the same degree of polymerization, prepared in the same manner such as by spray-drying and the same total solids content, the gel viscosity will vary depending upon the weight ratio of colloidal hydrolyzed cellulose to inulin. There is a point at which, all other factors being equal, increasing the weight ratio of colloidal hydrolyzed cellulose to inulin will decrease the viscosity of a gel, but further increase of the amount of the colloidal hydrolyzed cellulose present will again increase the viscosity of the gel.
This point will vary from composition to composition depending on the factors set forth above. For example, for a spray-dried composition having an average degree of polymerization of 9 and a total solids content of 20 weight percent, the gel viscosity will begin to decrease when the amount of colloidal hydrolyzed cellulose is present in an amount of about 3%, will bottom out at about 30% colloidal hydrolyzed cellulose and will begin to increase when the amount of colloidal hydrolyzed cellulose present increases beyond 30%.
The composition according to this invention may be added to a food to replace some or all of the fat present in the food.
The composition, whether a powder or a paste, may be added to a food in an amount of from about 0.5% to about 10% or more, based on the weight of the composition plus food. The amount to be added will depend upon the nature of the food, whether the food is paste-like, such as mayonnaise, light such as whipped topping, or cheeselike, etc.
The composition, either a spray-dried powder of inulin and- colloidal hydrolyzed cellulose or a paste dispersion of inulin and colloidal hydrolyzed cellulose, is dispersed in water which has been heated to aid in dispersing the composition. The mixture is subjected to a high speed shearing in order to obtain a uniform dispersion. The other components of the food are then added and the composition mixed thoroughly. The reduced fat containing food may then be aged, refrigerated or packaged depending upon the type of food being prepared.
The amount of liquid added to the paste for use in a food depends on a number of factors. The amount of liquid added is influenced by the particle size of the paste components, the average degree of polymerization of the inulin present, the ratio of the colloidal hydrolyzed cellulose to the inulin and the amount of liquid already in the food. Example 10 is an example where a paste is added to water according to this invention.
The food which is prepared will have all of the normal ancillary ingredients present such as, stabilizers, preservatives, seasoning, emulsifiers, sweeteners, anti-caking agents, colorants and the like in the amounts normally present.
It is important that the pH of the gel or paste be maintained above about 3. If the pH is not maintained at that level, the inulin will be hydrolyzed into its component sugars causing the inulin composition to lose functionality.
The composition of this invention, whether it be inulin alone which has been spray-dried after receipt from the manufacturer, inulin as received from the manufacturer mixed with attrited hydrolyzed cellulose and subjected to high shear, spray-dried inulin with attrited hydrolyzed colloidal cellulose or inulin which has been mixed with attrited hydrolyzed cellulose and the mixture subjected to high shear and then spray-dried as a powder, may be added to a composition such as a food to thicken or gel the food or composition.
The foods in which the composition of this invention may be used are legion. For example, the compositions of this invention may be used to prepare confectioneries, goods to be baked, dairy products, dressings, emulsion foods, whipped toppings, cheeses and table spreads and many more.
In the examples which follow, the following inulins are used. The inulin degree of polymerization given is obtained from the various manufacturers.
Raftiline(copyright) ST has an average degree of polymerization of 9 and is obtainable from Orafti. Frutafit (Inulin-HD) has an average degree of polymerization of 9 and is obtainable from Imperial Suiker Unie. Fibruline LC is believed to have a degree of polymerization of about 14 and is obtainable from Cosucra S.A.
The viscosity of gels formed using the compositions of this invention is set forth in the examples. Generally, the more viscous the gel, the greater is the efficacy of the composition. The examples are also useful to establish viscosity profiles at different solids levels and different inulin to colloidal hydrolyzed cellulose wetcake ratios. These profiles are useful to select a solids level content and an inulin to colloidal hydrolyzed cellulose wetcake ratio for a specific food application, e.g., a reduced fat spread, non-fat frozen dessert and the like.
In order to more fully illustrate the nature of this invention and the manner of practicing the same, the following examples are presented.
Examples 11 through 17 and 21 through 24 have not actually been conducted. However, if they were conducted, it is believed they would be conducted in the manner described with the results described.